fs/dax: Reject IOCB_ATOMIC in dax_iomap_rw()

The DAX write path does not support IOCB_ATOMIC, so reject it when set.

Suggested-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

diff --git a/fs/dax.c b/fs/dax.c
index 4229513806bea094904b5e50db141b10c2c0c915..20ecf652c129d1aa5d19babd90943f774aa866d3 100644 (file)
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1743,6 +1743,9 @@ dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
        loff_t done = 0;
        int ret;
 
+       if (WARN_ON_ONCE(iocb->ki_flags & IOCB_ATOMIC))
+               return -EIO;
+
        if (!iomi.len)
                return 0;